South Korea's Kospi and Taiwan's Taiex stock markets have reached record highs in 2026, fueled by surging demand for semiconductors and artificial intelligence hardware. The rallies are largely attributed to the dominance of a few major companies: TSMC now represents over 40% of the Taiex benchmark, while Samsung Electronics and SK Hynix together account for a record 42.2% of the Kospi as of May [1]. Samsung Electronics' market capitalization surpassed $1 trillion last week, reflecting intense investor interest in AI-linked stocks [1].
The Kospi index has surged more than 80% this year, repeatedly hitting new highs, while the Taiex has also posted multiple records as investors flock to semiconductor-related equities at the heart of the AI boom [1]. According to Goldman Sachs strategist Tim Moe, Taiwan is 'well over 80%' exposed to AI-related revenue streams, and South Korea is around 60% exposed, highlighting the centrality of the AI hardware theme in driving these markets [1].
However, analysts are raising concerns about the risks associated with such high market concentration. The heavy reliance on a narrow group of exporters means that index-level gains may not reflect broad domestic economic strength, but rather the earnings power of a few large companies [1]. This concentration could amplify volatility and leave both markets vulnerable to shocks such as geopolitical tensions, supply chain disruptions, or a slowdown in data-center spending [1]. Moe specifically warned about risks from supply disruptions, political backlash against AI infrastructure, capital-market stress, and technological disruption from new chip designs [1].
Taiwan and South Korea's central roles in the global semiconductor supply chain make them particularly susceptible to disruptions in specialized chemicals, photoresists, and gases, which could halt production and trigger sharp stock corrections if supply is interrupted [1].
CONCLUSION
While South Korea's and Taiwan's stock markets are experiencing unprecedented gains driven by semiconductor and AI demand, analysts caution that extreme concentration in a handful of companies poses significant risks. Market participants should be aware that these record rallies may be vulnerable to external shocks and supply chain disruptions, potentially leading to increased volatility.